$ { \left[\begin{array}{rr}{1} & {-2} \\ {1} & {-2}\end{array}\right]+\left[\begin{array}{rr}{2} & {2} \\ {2} & {0}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{1}+{2} & {-2}+{2} \\ {1}+{2} & {-2}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{3} & {0} \\ {3} & {-2}\end{array}\right]}$